A thermoelectric conversion element can convert thermal energy into electrical energy by the Seebeck effect. By using such energy conversion characteristics, exhaust heat discharged from industrial and commercial processes and movable bodies can be converted to effective power, and hence thermoelectric conversion elements have been attracting attention as energy-saving techniques in consideration of environmental problems.
In general, the thermoelectric conversion element is configured by bonding a plurality of thermoelectric conversion materials (p-type semiconductor and n-type semiconductor) to an electrode. The thermoelectric conversion element is manufactured in such a manner that a sintering material is filled in a space formed by left and right dies and upper and lower punches, and that, while the sintering material is pressed from upper and lower sides with the punches, an electric current is directly applied to the punches (pulse energization). In this way, since instead of heating the sintering furnace, Joule heat is generated by flowing the electric current, heating is performed only in a narrow range, so that sintering time is shortened and further temperature unevenness can be reduced.
Such pulse energization sintering is disclosed, for example, in Patent Document 1. Further, a method for manufacturing a thermoelectric conversion element by bonding thermoelectric conversion materials to electrodes is disclosed, for example, in Patent Document 2 (especially, see FIG. 14 in Patent Document 2).